Postgres Sql 在查询中获取有限制的记录总数

Question

我创建了一个 table 并尝试从 table 记录创建一个 json 数组，其中它将 return JSON 数组作为 {"total_record":2222,data[{row 1 data},{row 2 data}]}

下面是相同

的查询

SELECT row_to_json(selected_records)::text AS data
FROM  (   
   SELECT min(total_count) AS total_count
        , array_to_json(array_agg(row_to_json(ROW(name,id,gender)))) AS data
   FROM (
      SELECT *
           , count(*) over () AS total_count  -- shouldn't show up in result
      FROM   test

      GROUP  BY ID
      LIMIT  1
      ) records
   ) selected_records;

但我是如何得到这样的 json

{"total_count":277938,"data":[{"f1":"Carol Rau","f2":1,"f3":"M"}]}

我需要列字段名而不是 f1,f2,f3

{"total_count":277938,"data":[{"name":"Carol Rau","id":1,"gender":"M"}]}

相同的 DDL：

create table public.test (name varchar, email varchar, phone bigint, address varchar, gender varchar, id serial primary key) 
INSERT INTO "public"."test" ("name", "email", "phone", "address", "gender", "id") VALUES ('Carol Rau', 'Computers, Electronics & Games', '1000000000', 'Suite 843 489 Annabell Islands, North Katlynland, UT 90089-0425', 'M', '1');
INSERT INTO "public"."test" ("name", "email", "phone", "address", "gender", "id") VALUES ('Vicente Sipes', 'Games', '1000000000', 'Suite 870 21754 Dare Ville, Thielstad, WA 97243-0588', 'M', '2');
INSERT INTO "public"."test" ("name", "email", "phone", "address", "gender", "id") VALUES ('Jadyn Kris', 'Kids', '1000000000', '5136 Harmon Dale, Jeramiemouth, VT 17688', 'M', '21');
INSERT INTO "public"."test" ("name", "email", "phone", "address", "gender", "id") VALUES ('Melyna Lueilwitz', 'Automotive, Music & Outdoors', '1000000000', 'Suite 578 0765 Paucek Meadow, Torphyborough, AR 41921', 'M', '22');
INSERT INTO "public"."test" ("name", "email", "phone", "address", "gender", "id") VALUES ('Phoebe Herzog Sr.', 'Movies', '1000000000', '82869 Carrie Ridges, East Tavaresmouth, AR 62150', 'M', '23');
INSERT INTO "public"."test" ("name", "email", "phone", "address", "gender", "id") VALUES ('Cierra Luettgen', 'Toys', '1000000000', '326 Maida Pine, Aylamouth, IL 03742', 'M', '90');

Answer 1

已编辑

select row_to_json(t) from (
  select
    (select count(*) from public.test) as total_count,
    (select json_agg(row_to_json(tt))
       from (select name, id, gender from public.test limit 1) tt) as data
) t

Postgres Sql 在查询中获取有限制的记录总数

Postgres Sql fetch total nos of record with limit in query

postgresql

postgresql-9.4